I've had the 3C solution from Eastern b for a couple of years, and its excellent, well-made, and enough for most purposes. I'v still got one circuit unused! If you aren't using the Suzuki heated grips circuit you can always use that as a switched circuit, too, extend it from its connector behind the radiator to the front...
Lot of electrical additions to a bike do better direct to the battery (maybe with an extra fuse and/or a relay) anyway...
I also use my permanent connector for the Optimate charger for access to power, and with a ciggy-type charge point, that's a ton of power!